Integral Logistics Management — Operations Management and Supply Chain Management Within and Across Companies

18.2.3c Quality Planning: First-Pass Yield (FPY), SIPOC diagram and Critical-to-Quality (CTQ) matrix 

Intended learning outcomes: Explain the first-pass-yield thinking. Describe the SIPOC diagram and the CTQ matrix.

Continuation from previous subsection (18.2.3b).

The first-pass yield (FPY) is the percentage of results (i.e., units) that pass on first test — that is, without requiring rework.

An increased FPY entails reduced costs due to rework. Development is successful if the defect rate can be rapidly reduced once the product is introduced or if it is zero from the start (zero-defect rate). As the development process is essentially a creative one and can contain errors, defects can always be expected with an innovation. The need to reduce development time and development costs also speaks against a zero-defect rate. For these reasons, defects will be accepted at first, and importance will be placed on reducing this rate rapidly once the product is introduced. Then, it is important to have sufficient capacity for rapid revision and a comprehensive information system for capturing the responses of the first customers.

For example, during quality planning, quality requirements — together with the original ideas about the requirements — are translated into an offer to customers that describes the company’s product or service. This description, which is often a component of a contractual agreement, can already deviate decisively from the customer’s expectations, so that at this point in time at the latest, a decision must be made as to whether the individual steps of quality planning should be repeated (non-first-pass yield).

With this, the Define, or quality planning, phase entails capturing the relevant processes. In Six Sigma, this is represented in SIPOC diagrams.

The SIPOC diagram shows the system with Inputs, Process, and Outputs as well as the Suppliers and the Customers. See Figure

In this phase, the diagrams show the actual state, before all work begins. On the basis of the diagramming of the process, the critical elements will then be worked out.

Fig.       SIPOC diagram.

CTQs (Critical to Quality) are key measurable characteristics (e.g. regarding quality, costs, or delivery), elements of the process, or practices that have a great and direct effect on the customer’s perception of the quality of a product or service. See Figure

Fig.       CTQ matrix.

CTQs are usually represented in a matrix, or CTQ tree, that shows the (sub-)products and their critical attributes on the horizontal axis. The processes that can lead (or not lead) to these critical characteristics, process elements, or practices are shown on the vertical axis.

The Six Sigma method revisits the outcomes to be delivered (deliverables) again and again:

  • Are the project teams well trained and motivated?
  • Have the customers been identified and CTQs defined?
  • Has the project management handbook been drawn up?
  • Have the business processes been diagrammed appropriately (e.g. using SIPOC)?

Each of these questions is revisited repeatedly throughout the entire phase in greater detail, in order to ensure that they are handled comprehensively.

Course section 18.2: Subsections and their intended learning outcomes

  • 18.2 Quality Management Tasks at the Operations Level

    Intended learning outcomes: Produce an overview on the Deming Cycle (PDCA Cycle) and the Shewhart Cycle as well as the Six Sigma Phases. Present the phases of quality planning, control, assurance, and activation of the Deming Cycle. Describe the Six-Sigma phases of define, measure, analyze, improve, and control. Differentiate between continual improvement and reengineering.

  • 18.2.1 The Deming Cycle (PDCA Cycle) and the Shewhart Cycle

    Intended learning outcomes: Produce an overview on The Shewhart cycle developed in statistical quality control. Present the Deming cycle. Describe quality management tasks in the Deming cycle.

  • 18.2.2 DMAIC — The Six Sigma Phases

    Intended learning outcomes: Present DMAIC, the Six Sigma phases. Describe the tasks in the Six Sigma phases. Differentiate between DMAIC, RDMAIC, DMAICT, and DMADV.

  • 18.2.3 Quality Planning: PDCA Plan Phase — DMAIC Define Phase

    Intended learning outcomes: Identify the cause of differences between stakeholders’ expectations and actual product or process characteristics.